Modern electronic equipment such as televisions, telephones, radios and computers are generally constructed of solid state devices. Solid state devices are preferred in electronic equipment because they are extremely small and relatively inexpensive. Additionally, solid state devices are very reliable because they have no moving parts, but are based on the movement of charge carriers.
Solid state devices may be transistors, capacitors, resistors and the like. These devices are fabricated on a substrate and interconnected to form integrated circuits. Device fabrication typically includes depositing, patterning and etching conductor, semiconductor and insulator layers that make up features of the device.
Etching of metal and poly-metal gate structures is known to damage the underlying gate oxide, degrading its integrity and leading to device failure. To restore gate oxide integrity (GOI), post-gate-etch oxidation processes have been used. These processes, however, can oxidize the metal and poly-metal gate structures, resulting in high sheet resistance. To prevent gate oxidation, a selective oxidation process that uses N.sub.2 diluted in H.sub.2 /H.sub.2 0 ambient has been proposed. Selective oxidation is unproven for use in large scale manufacturing and impractical because of the difficulty in achieving sufficient oxidation at the bottom of the gate to remove etch damage while preventing the gate from oxidizing.